For whatever reason, roller skates having wheels arranged in a single line have largely displaced those with wheels at four corners of the skates. So-called "in-line" skates customarily have three to five (or more) wheels arranged fore-to-aft and are less stable and more difficult to stop than their four-wheel-cornered predecessors.
Nowadays in-line skates are usually braked by tipping the front end upward, sacrificing both precision and safety, in order to press a brake pad on the aft end down onto the underlying skating surface. See an improvement by Pellegrini and Tormens in U.S. Pat. No. 5,511,804.
Other inventors received U.S. patents for such contributions to skate brakes as (a) brake shoe against tire/wheel perimeter, Slusher U.S. Pat. No. 1,687,739, Mirick U.S. Pat. No. 1,801,205, Means U.S. Pat. No. 2,027,427, Riggs U.S. Pat. No. 4,300,781, Krantz U.S. Pat. No. 4,805,936, Dettmer U.S. Pat. No. 5,171,032, Mitchell U.S. Pat. No. 5,253,882; (b) brake against another part of wheel, Krausz U.S. Pat. No. 4,076,266, Scheck U.S. Pat. No. 4,108,451, Smathers U.S. Pat. No. 5,280,930; (c) brake shoe against aiding wheel forced onto the underlying pavement, Klukos U.S. Pat. No. 5,511,803; (d) braking roller against tire/wheel perimeter, Eubank U.S. Pat. No. 920,848 and U.S. Pat. No. 926,646, Murga U.S. Pat. No. 5,069,462, Hoskin U.S. Pat. No. 5,183,275, Moldenhauer U.S. Pat. No. 5,411,276. The foregoing constitutes my best present knowledge of the skate art. The bicycle art provides some analogous or counterpart--yet different--features.